(function(f) {

    'use strict';
  
    /* istanbul ignore else */
    if (typeof exports === 'object' && exports != null &&
        typeof exports.nodeType !== 'number') {
      module.exports = f ();
    } else if (typeof define === 'function' && define.amd != null) {
      define ([], f);
    } else {
      var base64 = f ();
      var global = typeof self !== 'undefined' ? self : $.global;
      if (typeof global.btoa !== 'function') global.btoa = base64.btoa;
      if (typeof global.atob !== 'function') global.atob = base64.atob;
    }
  
  } (function() {
  
    'use strict';
  
    var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
  
    function InvalidCharacterError(message) {
      this.message = message;
    }
    InvalidCharacterError.prototype = new Error ();
    InvalidCharacterError.prototype.name = 'InvalidCharacterError';
  
    // encoder
    // [https://gist.github.com/999166] by [https://github.com/nignag]
    function btoa(input) {
      var str = String (input);
      for (
        // initialize result and counter
        var block, charCode, idx = 0, map = chars, output = '';
        // if the next str index does not exist:
        //   change the mapping table to "="
        //   check if d has no fractional digits
        str.charAt (idx | 0) || (map = '=', idx % 1);
        // "8 - idx % 1 * 8" generates the sequence 2, 4, 6, 8
        output += map.charAt (63 & block >> 8 - idx % 1 * 8)
      ) {
        charCode = str.charCodeAt (idx += 3 / 4);
        if (charCode > 0xFF) {
          throw new InvalidCharacterError ("'btoa' failed: The string to be encoded contains characters outside of the Latin1 range.");
        }
        block = block << 8 | charCode;
      }
      return output;
    }
  
    // decoder
    // [https://gist.github.com/1020396] by [https://github.com/atk]
    function atob(input) {
      var str = (String (input)).replace (/[=]+$/, ''); // #31: ExtendScript bad parse of /=
      if (str.length % 4 === 1) {
        throw new InvalidCharacterError ("'atob' failed: The string to be decoded is not correctly encoded.");
      }
      for (
        // initialize result and counters
        var bc = 0, bs, buffer, idx = 0, output = '';
        // get next character
        buffer = str.charAt (idx++); // eslint-disable-line no-cond-assign
        // character found in table? initialize bit storage and add its ascii value;
        ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
          // and if not first of each 4 characters,
          // convert the first 8 bits to one ascii character
          bc++ % 4) ? output += String.fromCharCode (255 & bs >> (-2 * bc & 6)) : 0
      ) {
        // try to find character in table (0-63, not found => -1)
        buffer = chars.indexOf (buffer);
      }
      return output;
    }
  
    return {btoa: btoa, atob: atob};
  
  }));